Re: [sv-bc] RE: Clarification for `1 usage in unpacked array concatenation

I'm not sure if Dave's interpretation comes from explicit LRM rule.
LRM for says only that UAC: elements shall be interpreted as : "An item 
whose self-determined type is assignmentcompatible with the element type 
of the target array shall represent a single element" but does not say 
how assignment should be performed. IMHO each element assignment should 
be done according to general SV  rules so A[0] would be 4'b1111 
according to Dave interpretation special assignment  similar to vector 
concatenation should be done.
Maybe I'm missing something but imho this case is in grey/undefined area 
of LRM. I think that rule cited above was added to define cases where 
element by element assignment are possible vs cases other cases possible 
in UAC, not to define assignment rules

DANiel

W dniu 7/23/2014 4:25 PM, Rich, Dave pisze:
>
> The operands in an unpacked array concatenation are self-determined, 
> just like Verilog integral concatenation. So 1'b1 should be the 
> result. Assignment patterns are context determined. This is one of the 
> key distinctions between the two forms.
>
> Dave
>
> *From:*owner-sv-bc@eda.org [mailto:owner-sv-bc@eda.org] *On Behalf Of 
> *Goel, Rohit (Noida MED RTLC Synthesis)
> *Sent:* Wednesday, July 23, 2014 3:49 AM
> *To:* sv-bc@eda.org
> *Subject:* [sv-bc] Clarification for `1 usage in unpacked array 
> concatenation
>
> In SV 1800-2009 concatenations could be used as source expressions for 
> unpacked arrays (section 10.10). I have a query regarding usage of `1 
> in unpacked array concatenation. If the RTL has something like below
>
> logic [3:0] A [0:0];
>
> initial
>
> begin
>
>                A = {*'1*};
>
> end
>
> Does this mean that the value of A[0] after assignment will be "1111" 
> or will it be "0001"?
>
> Thanks & Regards
>
> Rohit Goel
>
>
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